The different types of collagen that are present in the cornea, sclera and lens capsule of bovine, rabbit and human eyes will be quantitatively estimated. The types of collagen present will be determined by solubilizing the tissues with pepsin, and fractionating the dissolved collagen molecules. The types of alpha-chains present will be identified by gel electrophoresis and confirmation of the chain types will be made by electrophoresis of the cyanogen bromide peptides and by preparation of the SLS aggregates for identification by electron microscopy. The disposition of the collagen types in the tissues will be studied by immunofluroescent techniques for light microscopy and with antibody-bound peroxidase for investigations at the electron microscope level. These techniques will require the preparation of type-specific antisera for the collagens detected. The appearance of the collagen types will be studied as a function of development stages in the bovine and the rabbit eyes, both by histological analysis and by pulse labeling with radioactive amino acids administered to newborn animals or to organ cultures. When the normal complements of collagen in the tissues are determined, exploratory studies will be made of the collagens appearing in abnormal circumstances such as corneal scars and retrocorneal fibroplasia. We will also study the collagen types as corneal scars and retrocorneal fibroplasia. We will also study the collagen types in normal sclera and anterior and posterior sclera of extreme myopes and we will attempt to define chemical changes in the collagen of the scleral envelope in a research program designed to investigate the structural correlates of myopia.